The invention relates to a worm gear unit having at least one worm shaft displaceable in the axial direction.
As already described in DE 198 11 977.1 (date of application: Mar. 19, 1998), worm gear units are classed as standard gear units and are used in a multiplicity of applications at the most widely varying transmission ratios. Depending on the application, worm gear units with or without self-locking may be selected.
In some applications, for example when a worm gear unit is used as a step-down gear unit in electric steering aids, it is necessary to keep the play of the worm gear unit slight in order to transmit a drive force directly and without play to the output. High-precision manufacture of the worm and the worm gear of the worm gear unit or even the use of certain tooth-flank forms could be considered as possible measures for reducing the play. However, this has the disadvantage that this is complicated and thus very cost-intensive precisely during the mass production of worm gear units, in particular for the use of electric steering aids in vehicles.